Energy infrastructures

What is it:

This technology contributes to the energy transition through greenhouse gas emissions reduction. Furthermore, renewable energy plants are also emerging as a driver of inclusive economic growth. They include both, small-scale electricity production facilities from renewable sources (photovoltaics, wind, biomass, etc.), or from cogeneration or trigeneration facilities, where heat and electricity are produced and, where appropriate, cold, increasing the overall performance of the system.

Main renewable energy technologies:

• Solar photovoltaics: it uses solar radiation for electricity production, in different configurations.
• Wind turbines: they take advantage of the wind speed for electricity production.
• Hydroelectric plants: mini hydropower plants or small waterfalls utilized for electricity production, with powers of up to 10 MW.
• Biomass plants: based on the combustion of biomass (solid, liquid or gaseous) to produce electricity in thermal plants. This biomass can come from energy crops or from forest, industrial, agricultural, livestock, residues, etc.).

Companies cooperation benefits:

Several companies within the same park could invest in one such plant: the costs and benefits are shared, and the risk associated with the investment are reduced for all.

Also, the most suitable position could be identified (i.e. most irradiated roofs, most windy area, etc.), making the investment more efficient.

What is it:

Any bioelectricity generation demands a conversion of the biomass so that it can be used for the bioelectricity generation.

Different working fluids are used:

• Steam is the most common working medium in steam turbines, and steam engines.
• Organic oil vapour in Organic Rankine Cycles (ORC)
• Air, helium or hydrogen in Stirling engines
• Air in hot air turbines

There are different technologies for energy production:

• Combustion is a well-established and fully commercial biomass conversion technology.
• Anaerobic digestion is commercially available and is widely used.
• Gasification can still not be considered as fully commercial for biomass, despite many intensive research and demonstration programs that have done research in the past several decades.
• Pyrolysis can also still not be considered fully commercial for biomass, and the aim of pyrolysis is usually not generation, but bio-oil or charcoal production.

The most used (dominating) CHP system for biomass are combustion and steam turbines while steam engines are a commercial alternative in the small-scale segment.

Companies cooperation benefits:

In this framework, the joint purchase and operation of a CHP plant could be interesting for the different companies in a park.

Possibility to share the initial investment.

A CHP plant is most efficient when both its electrical and thermal production are fully used. This target could be achieved by providing heat and power to different companies, according to their needs.

A cooperative approach has the ulterior advantage of ensuring a more stable functioning of the plant: ideally, it is always operated to its nominal point guaranteeing maximum efficiency and a longer lifespan, supplying multiple industrial facilities according to their demands.

What is it:

Many companies try to identify solutions to improve their plants' performances and processes from an energy point of view, aiming to reduce energy related costs. Investment related to common/shared areas and the analysis of how single company measures could be integrated in the larger framework.

The energy efficiency measures that are normally carried out are the following:

• Lighting system
• Refurbishment of shared buildings
• Improvement of the internal electric network

Companies cooperation benefits:

As all the companies within the park premises may have to pay the electricity costs of common areas, all of them would benefit from an investment to improve the energy efficiency of these spaces.

An analysis of these measures collaborating with neighbouring companies could maximize the impact thanks to a more holistic approach.

What is it:

Making use of waste heat energy currently discharged into the atmosphere is one of the largest sources of clean, fuel-free, and inexpensive energy available.

Methods to produce such energy are:

• Kalina Cycles (KC): KC is based on Rankine cycle, utilizes a mixture of ammonia and water as working fluid. The operating temperature range is 100 ºC to 500 ºC. It is 25 % more efficient than ORCs.
• Organic Rankine Cycle (ORC): ORC utilizes an organic working fluid with high vapour pressure, low boiling point, higher mass flow, and higher molecular mass in comparison with water. These systems can harvest waste energy at a lowest temperature of 150 ºC. ORC systems have higher efficiency at lower temperatures than SRC.
• Steam Rankine Cycle (SRC): The most important and common waste heat recovery. that produces steam from waste heat is the Steam Rankine Cycle, driving a steam turbine. The operation of a steam turbine recovery boiler is based on thermo-dynamic process called “Rankine Cycle”. It is not appropriate for temperatures below 260 ºC.

Rankine Cycle.

Source: Zeb K. et al. A survey on waste heat recovery: Electric power generation and potential prospects within Pakistan. Renewable and Sustainable Energy Reviews 2017;75:1142.

In addition to these WHR techniques, there are number of advanced technologies in research stage that directly harvest electricity from waste heat. These technologies are:

• Thermo-photovoltaic devices
• Piezoelectric processes
• Thermoelectric processes
• Thermionic processes
• Brayton cycle
• Sterling engine

Some energy harvesting technologies and optimal temperature ranges.

Companies cooperation benefits:

Power plants recovering heat for electric generation are generally characterised by high capital costsFor this reason, a joint investment could be a profitable solution to address a large amount of waste heat in the park, generated by a single plant or multiple ones: as the investment is shared between more than one company, the electricity produced by the plants could be shared according to different parameters.

What is it:

Electricity storage makes possible a transport sector dominated by electric vehicles, solar home systems and 100% renewable mini grids. Along with solar and power generation, it will allow sharp decarbonisation in key segments of the energy market.

At very high shares of variable renewable electricity, electricity will need to be stored over days. Energy storage by companies is possible so as not to have to buy it in the future and be able to reuse the self-produced product.

Energy storage functions.

Source: International Renewable Energy Agency. Electricity Storage And Renewables: Costs And Markets To 2030, 2017.

Companies cooperation benefits:

The economic benefit behind the purchase of electrical storages by an industrial facility is that they can target the reduction of electricity costs both via the interaction with the local grid or allowing a smoother employment of the power production assets.

Two main actions could be performed regarding the Distribution System Operator (DSO):

• The end users may reduce their electricity costs by employing electrical storages to reduce peak power needed from the grid during the day and to buy the needed electricity at off-peak times.
• They allow increasing self-consumption of local power generation from RES: self-consumption can lower the overall costs of the energy system through load shifting if storage and demand response are managed using ICT algorithms to control it.

The investments could be shared both in terms of capital and operational costs and the storages can be in a common space in the most convenient location. Moreover, they can be operated in a joint way to serve other electrical facilities as a buffer, in order to maximise their utilisation and impact.

What is it:

TES is a technology that stocks thermal energy by heating or cooling a storage medium, so that the stored energy can be used later for heating and cooling applications and/or power generation. It is possible to consider thermal storage on the hot and/or cold side of the plant.

• The former allows the storage of hot water from the collectors to be supplied to the generator of the absorption chiller or directly to the users. Hot tank with a temperature ranges from 80 ºC to 90ºC.
• The latter allows the storage of cold water produced by the absorption chiller to be supplied to the cooling terminals inside the building. Cold tank with a temperature ranges from 7 ºC to 15 ºC.

Thermal storages main characteristics.

TES systems can be installed as either centralized plants or distributed devices.The first one is designed to store waste heat from large industrial processes, conventional, combined cycles and renewable power plants. While distributed devices are usually buffer storage systems to accumulate solar heat to be used for domestic and commercial buildings.

Companies cooperation benefits:

Advantages of using TES in an energy system include higher overall efficiency and better reliability, and it can lead to better economic benefits in the form of investment, running costs reductions and less pollution.

Furthermore, there is the possibility of exploiting multiple areas in the park, as well as to the optimisation of benefits deriving from multi-company analysis for their utilisation.

What is it:

Reactive power compensation (expressed in Volt-Amperes) does not involve a transfer of energy. It is transferred from the source to the load and then returns from the load to the source, the average power supplied is zero.

This means, reactive power is positive during one half cycle and negative during another half cycle on the AC waveform. Reactive power compensation is required to keep the system voltage within appropriate limits. The main reasons leading to the necessity for RPC in the electric systems are:

• The voltage regulation
• Increased system stability
• Better utilization of machines connected to the system
• Reducing losses associated with the system

Charges for reactive power are applied differently in EU countries, but typically there are two different schemes:

• Reactive Tariff: A regular tariff rate is applied to each MVARh of reactive energy produced or consumed.
• Penalty: Reactive energy produced or consumed is charged only if some predefined conditions are met.

Companies cooperation benefits:

While the purchase of a device for a single company may not lead to savings, its acquisition by multiple companies could be beneficial, leading to higher efficiency and economic savings.

What is it:

Power-to-Gas is an innovative concept that couples the electricity and gas networks allowing for the flexible handling of excess and shortage of electricity generation.

The Power-to-Gas concept is about converting electrical power into a gaseous energy carrier such as hydrogen or methane. In the picture is shown a scheme of the power-to-gas concept.

Source: https://www.dnvgl.com/

Its core component is an electrolytic cell in which water molecules are split into hydrogen and oxygen by applying electric current. The hydrogen could be used afterwards directly as feedstock or fuel in the industrial or transport sector.

Furthermore, it can be converted to methane, that is, via a methanation process making use of captured carbon dioxide.

Companies cooperation benefits:

Power-to-Gas has an economic potential in various sectors, some more advanced than others:

• Balancing services: rapid response electrolysers could take over a part of this service, providing network stability and maintaining a competitive Frequency Containment Reserve.
• Energy storage: the energy storage functionality can be applied at different scales varying from small-scale applications that balance the output of a single wind turbine to large-scale storage. It is also very flexible with respect to the duration of an energy storage cycle.
• Chemical and processing industries: the supply of large industries with hydrogen from Power-to Gas installations currently costs twice as much as to the conventional production process.
• Transport sector: represents the most promising application for the use of green hydrogen now and could be the first target for large scale deployment of the technology.

Power-to-Gas applications may be particularly interesting in the framework of an industrial park that has already installed, or which is willing to install other assets such as: relevant renewable sources plants, H2 vehicles, flue gas capture, etc.

What is it:

There are many options for increasing electricity system flexibility, including increasing supply and demand flexibility, developing energy storage technologies and systems services and increasing the transmission capacity of the national grid and interconnections to other countries.

Demand flexibility may be facilitated by the integration of the electricity system with the heating and gas systems. Such integration offers an opportunity to increase the electricity consumption during hours of very high electricity production from variable electricity sources by producing gas or heat.

Power-to-Heat refers to heat production from electricity through heat pumps or electric boilers, and the application of this technology in the district heating sector.

Companies cooperation benefits:

The cooperative benefits deriving from power-to heat can be found both in their economies of scale when purchasing the technologies to be installed and in the optimal exploitation of park’s existing asset.

What is it:

Waste heat recovery is one of the most efficient way of employing heat pump technology. By recovering the waste heat and increasing the temperature to a useful level, generally high performance and short payback can be achieved.

Heat could be recovered from multiple sources: industrial processes, electricity production plants, hot flues, etc.

The related characteristics in terms of heat vector and temperature could be very different requiring different technologies to be recovered, the recovery of waste and its enhancement could represent an added value to different companies within a park.

In particular, a cooperative approach could be identified in a shared investment in order to buy the required heat pump/heat exchanger: to this end two or more companies would convey their waste heat fluxes in order to enhance their temperature and successively reuse them.

A different scheme that can be envisaged is the selling of the recovered and enhanced heat to another company in the same park, if the producer cannot profitably exploit it: different considerations have to be performed on the basis of the actual loads and requests of the various companies in each park.

Companies cooperation benefits:

A cooperative approach could be identified in a shared investment in order to buy the required heat pump/heat exchanger: to this end two or more companies would convey their waste heat fluxes in order to enhance their temperature and successively reuse them.